Hydraulic installation



Aug. 15, 1933. l A, PFAU 1,922,323

HYDRAULIC INSTALLATION Filed May 18, 1928 @bl d..

Patented Aug. 15, 1933 UNTTED STATES PATENT oFFica Y y1,922,323HYDRAULIC INSTALLATION 'Arnold Pfau, Milwaukee, Wis., assigner to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a Corporation ofDelawareY Application May 1s, 1928.` serialfNo. 278,886

` claims. (c1. 137-158) This invention relates in general to powerinstallations and it has particular relation to hydroelectric powerinstallations where the hydraulic machine is operative under or againsta widely 5, varying head.

Turbines of hydraulic power plants which are subjectto a highly variablehead such, for instance, as certain streams or the high Aand low tide ofthe ocean, suier a considerable loss in the w power developed. This isparticularly the case v with very low heads where even a slight changein the head amounts to quite a considerable portion of the full normalhead. For instance, if

or 50 revolutions, that is, half of theformer amount, when thehead hasdropped t0 1/i 0f the maximum head. -v l If the turbine is directlyconnected to an alter-v nating current generator, it should alwaysoperate at the'samenumber of revolutions, otherwise the number ofperiods orfrequency of the current would change, and this would renderparallel operation with other generators impossible. Therefore, if aturbine were normally designed for 1GO revolutions under 16 meters nethead, it would have to develop under 4 meters head, not 50 revolutions,but twice as much, that is, 100 revolutions, in order to produce currentof the proper number of periods or frequency. A turbine operating at aspeed which is 100 per cent higher than normal, however, shows, suchunfavorable hydraulic efc'iencies, thatit becomes unconnnercial tostilluse `a` turbine for. such operating conditions. v

The speed of the generator could be' maintained normal by using in stepsbelt drives or similar devices with proper transmission ratios. Thisarrangement, however, is impossible where large units are usedlandparticularly when the turbine and generator are directly coupled, whichis the 5ol most favorable mechanical solution.

Thek power developed by the turbine lis even more sensitively affectedby a change in the net head; rst, on account of the head itself, second,

on account ofv the discharge capacity. It is well known that f'QirQr--x/lIw/Hz, Where Q1=quantity of water under thehead HQ2=vquantity of Water under the head I-Iz,v and YHP1.HP2=H1.'\/1fH2.1/I2-Whr f HPr--power at head H1,. 1

HP2=power at `head H2.

is also subjected toa variation inthe eiciency ofV the turbine, andYthis deviates morejfrom the best value as the numberof revolutionsorspeed is greater or less than the normal speed. Therefore, if the poweror capacity, for in-V stance, under 16 meters net head, is 4000 HP, thenit isaccording to the above formulae, only 500 HPunder 4 meters, andthisdoes not as yetcon-v sider the loss of` power due to reduced elliciency.Now, if the turbine mustmaintain its 100 revolutions, it would have torun twice as fastas isnecessary in order to maintain its normalefficiency. Therefore, the eiciency will dropvto4 such extent vthatnothing `will be left` of the 500 HP. In` othergwords,the'turbinewillproduce no power and, therefore,v represents'a `jdead capitalinvestment. 5

cernedwith theprovision of an improved powerV system; for the.economical utilizationv of" aV power v sourcek of relatively widelyvarying availablehead or'pressure, and it more particularly involves'the use of a plurality of `power units of such individualdesign as tocapacity and normal operating head or pressure under which the unitsoperate, each `atdts predetermined desred'speed,

as to insure operationof thesystem under dif'` ferent headsrorpressuresv Yunder conditions of maximum efliciency; And the presentyinven.

tion is further concerned with features of auto.

matic contrelof a system involving a plurality of turbines Vdriving orsupplying power toa common load so as to yinsure operation' of. thevload, such asan alternating current generator, vat, a

controlled speed throughout full variation in the;` head independentlyVof whether one or more orallof the turbines supply power to theload,Aes- The capacity orpower of the turbine, however,`

. g `so ,y The invention of the present applicationiscon a pecially suchoperation as is desired to secure economical operation at high overalleiciency of the system. As a further feature, the control of a system,particularly a hydro-electric system, of the character described, as tothe necessary changes or operations required to accommodate for thedifference in head to which the turbines are subjected, vor othervariable characteristic, is rendered automatic in response to anoperating condition, such as the change in effective heador pressure onthe turbine.

It is an object of this invention to provide the above described andother related improvements in power systems, and more particularlyhydraulic power systems, and their operation, fea-v tures of theinvention being apparent from the accompanying description andthedrawing relative thereto, disclosing an embodiment of this' invention,and being more particularly pointed out in the claims herein. u

The illustrative showing of the drawing 1s a diagrammatic showing of. ahydro-electric sys-V nect'ed,`V through a permanent' orzreleasableclutch cennection,to hydraulicturbines 2and 3, of such different designas to secure most eiiicient operation under substantially differentheads and preferably capable oi producing substantially the same powerwhen each is subjected to its normal( operating head; "4 Vindicates 'asource of direct currentvoltage for supplying any -required variabledegree of excitation of the field of the generator 1. The circuit 6,supplied by the generator 1, is connected through a line switch 7, to analternating currentfload or distribution system'S. y

The turbines 2 and 3.may be of either the Francis type or open runner orpropeller type, and they may be controlled wholly asto the-wateradmitted thereto andthe power produced thereby may be regulated byvguide-vanes and actuating mechanism therefor of suitable conventionaltype.-

constant speedunder variable load conditions by 4its individualautomatic controlling means, the controlling means for the turbine 2being indicated.- generally at C2 and asimilar controlling means ,forthe turbine 3at C3; As indicated vin the drawing, there '-is present, asshown. schematically, a servo-,motor Miof well Yknown `construction,vsuch `as Vis used for controlling the guide-vane openings'of turbinesnThe regulating valve .VV receives ii'uid pressure, as indicated atK,.`and admitssame,laccordinglto the'position oi the. regulatingvalve'piston V1, either to apassage K1 communicating with the'front sideof the regulating piston M1 of` the servo-motor M,

or `to a passage K2 communicating with the rear side of the .regulatingpiston M1.' The `'desired actuation of'fthe turbine yguide-vanes orother controlling means for'the turbine-'A is transmitted from theregulating piston M1 of the servomotor M` in any suitable well knownmanner.

`For conveniencafa rod may be provided at the rear side of the pistonVand passing through a sealed -aperture in the rear end wall'of thecylinder, this rod being connected through a lever or crank M2 totheoperating rod 10 for the guidevane actuating mechanism of turbine 2or the operating rod 11` for the guide-vane actuating mechanism orturbine 3. s

The motion of the regulating piston M1 is transmitted to a'relay R. Aspeed governor P receives its revolutions'through a drive T from theturbine shaft and transmits the motion oi' the shifting collar or studof the governor to the floating lever V-P-R. As soon as the regulatfing'valve piston V1 is raised out Vof its mid position, fluid pressure Kreaches the frontI side K1 of the regulating piston M1, moving thelatterV until the regulating valve rpiston V1 is brought back to itsformer mid position. This is attained by the relay R and the floatinglever R-P--V in such a way that the motion to the `left of theregulating piston M1 produces an upward -motion of the end R of thefloating lever, causing the regulating valve piston V1 to be loweredafter it had iirst been raised by the speed governor.

By shifting the hand wheel R2 on the relay rod R1, it is possible tovariably determine the controlled speed of Yoperation Vof `each turbine,although for normal operation, the hand wheel occupies a single definiteposition on theV rod corresponding to that normal speed Nwhich insuresthe desired frequency of, currentproduced by the generator 1. Likewise,this provision for variably positioning the hand wheel R2v on the rod R1constitutes a means for shutting olf the supply of water to eachturbine, when it is desired to render either turbine inactive. Thenormally contemplatedoperation ofthe 1 system disclosed hereinincludes-the operation of the turbine'Z alone-while the head on thestorage source is between the values'Hm and Ha, the operation of bothturbines 2 and 3 while the availableA head is between the values Ha'andHb, and the operation of turbine 3 alone while the available headislbetween values 'Hb and Hc, the latter corresponding vto the minimumhead that is economically'utilizrable by the turbine 3f The design ofthe turbine 2 is such that quite efficient operation thereof at thenormal operating speed N may be secured -whilev the head occupies anyValue between Hm kand Ha; and the design of the turbine 3 is such as tosecure quite eflicient operation yfor any values of the head betweenthe-.values H11 and Hc; i' "In the range between the values Ha and Hb,

both turbines 2 and 3 operate at reduced efficiency and hence reducedoutput; `but,nevertheless,v thel Vtwo turbines together are capable ofproducing a required average amount of power corresponding to atleastthe normal output of .either of the turbines under its normal or mostefficient' operating head, Through this provision, a vsubstantial amountof power can be eX- tracted at Aa relatively high general or averageeiiciency` from a source of supply whose head is subject to variationover a relatively wide range, and this resultl may be secured with arelatively small capital investment.

Where the variation in head occurs relatively often or at a relativelyrapid-rata'it may be de'- may be secured through the use of control ap-150 paratus `of the character illustrated which includes the provisionof a float 12 in the head water of the turbine and a float 13 in thetail water of the turbine, with flexible cords or chains connected toeach of these floats and suitably guided and passing over pulleys fixedto jack shafts 14, 15, respectively, of aV mechanicaldifferential, theiloats 12 and 13 being balanced by suitable weights16 and 17,respectively, connected to the other end of the flexible cords attachedto the oats. The mechanical differential gear including the jack shafts14 and 15, has as its differentially driven element a gear 18 whichactuates a geared segment 19 connected to an indicating needle 21 whichmoves overa scale to give an exact indication of the difference in levelbetween the floats 12 and 13, and hence, the net effective head on theturbine or turbines The indicating needle 21 is mounted so as to moveover and in engagement with contacts 23 and 24. The contact 23 is sodisposed relative to the path of movement of the needle 21 that, whilethe needle is in engagement with the contact 23, the head on the storagesource is between the values Hm and Hb; and the contact 24 motor 29 forforward and reverse operation, de-

pending upon Whether the switch is in its upper closed position, asindicated in the drawing, or in its lower closed position. When theneedle 21 is in engagement with the contact 24, a circuit is closedthrough the energizing winding 31 of Aa reversing switch 32 havingbridging portions 34 and 35 serving to establish the operating circuitof an electric motor 36 for forward `or reverse operation, dependingupon Whether the switch is in its upper or lower closed position, theswitch being indicated in the drawing as being in its lower closedposition.

It will be noted that during a certain part of the travel of the needle21, corresponding fto an' available head on the storage source ofa valuebetween Hs and Hb, engagement is made by the needle 21 with both of thecontacts 23 and 24, under which circumstances the energizing Windings ofboth reversing switches 26 and 31 are closed' and the reversing switchesoccupyl their upper closed positions. A

Each of the motors 29 and 36 has its shaft provided with a pinion 52,the Asame being engageable with a gear 53 attached tothe adjusting wheelR2 on the relay rod R1 of the controlling means C2 and C3, respectively.In the motor circuit through the switch 26 in its upper position, islocated a switch 56 biased to closed positionand operable to openposition by an electro-magnet .having an energizing Winding 57; and inthe motor circuit closed through the switch 26 in its lower position,there is disposed a switch 58 biased to closed position and operable toopen position by an electro-magnet having an energizing I winding 59.The circuit of the energizing wind- Y ing 57 is completed through aswitchl; and the circuit through the energizing winding 59 is completedthrough'a switch 63. A o

A portion of the adjusting wheel Rg is provided with a projection Yorilange 67 adapted, through thereciprocation of the wheel or'nut on therelay rod R1,` to actuate the switches 61 and 63 Vto closed position,these switches being assumed to be biased toA open position. However,this operating means may include aloose connection or portion betweenthe element 67 :and the several switches, .which insures positiveoperation of these switches to both open and closed position; and theseswitches 6l and 63 may be of the snapoperated type. The preferable meansfor con-- necting the end of the lever V-P-R to the adjusting wheel R2includes a sleeve 68 held between flanges -on the rotatable adjustingwheel proper, this sleeve `being held against rotationk in any suitablemanner and having the end of the lever connected lto this non-rotatablesleeve. o The switch-actuating projection 67 is preferably mounted onthe sleeve 68.

In the circuit of the motor 36 when closed through the switch 32 in itsupper position, there is provided a switch 71 biased to closed positionand actuatable to open position,'as indicated, by an .electro-magnet'having an energizing winding 72; and in the motor circuit closedthrough the switch 32k in its lower position, there is provided a switch73 vbiased to closed position, as indicated, and actuatable to openposition vby an electro v magnet having an energizing winding 74. Thecircuit of the energizing windings 72 and 74 are closed by switches 61and 62, respectively, both biased to open position and moved to closedpositheillustrative disclosure, the turbine 2V is operative to drive thegenerator 1, the turbine 3 at this time beinginoperative, having beenreni dered `so through the actuation of the guide-vanas or other Vinletregulating device to closed position by its controlling means c3, thehand when R2 of'which is moved to its lowest position bythe electricmotor 36. This operating condition continues while the available head onthe storage source remains above the'valueHa, corresponding to the lowerlimit at which a substantial load can be efficiently supplied by lthegenerator 1 when driven by the turbine 2 alone. On reaching the headvalue corresponding to Ha, the needle 21, while maintaining engagementwith the contact23, now 'also makes engagement with the contact 24.KVThrough this latter engagement, wherein itcompletes the energizingcircuit of the las winding 31, the reversing switch 32 is actuated to iits upperclosed position; With the switch V32in tion of the 4controllingmeans Caas includes mov ing'the adjusting nut or hand wheel Raupwardlyupon the relay rod R1, toga position wherein it actuates the switch 61to closed position, thus causing opening of the switch 71 and stoppageof the motor 36, this position oi the hand wheel R2 .corresponding tothat setting of vthe, end R of the lever V-P-R which corresponds. withthe normal speedfof operation or the turbine and genera-tor l. With thiscondition existing, the turbine 3 assumes a portionof the load and thusassists in .driving the generator 1..' At this time, each of theturbines 2, 3 continues to' supply a proportionate share of the variableload, the turbines being controlled by their individual speed regulatingmechanism. Y

If the available head on the storage source continues to drop to a valuecorresponding to Hb, the indicating needle at this time breaksengagenient with the contact 23, thus deenergizing. the winding l and.permitting reversing switch .25 to drop to its lower closed positionwherein the operating circuit or the Yrnotor 29 is closed to produceoperation of the latter ina reverse direction. The eil'ect oithisoperation on the controlling means Czofthe turbine 2 is to shift theadjustable hand wheel R2 downwardly upon its .relay rod R1 to a positioncorresponding to an inactive condition of the turbine 2 wherein theguide-varies or other inlet controlling means Aare closed. As theadjustable hand wheel R2 reaches Aits vlower limiting positioncorresponding to a rendering of the turbine 2 inactive, the limit switch63 operatively associated with the hand wheel R2 is moved to closedposition wherein it energizes the winding 59 causing opening of theswitch 58 in the motor circuit and consequent stoppage vof the saine. y

Under these conditions, the turbine 3 is .alone eiective to drive thegenerator 1;.and this condition exists while the available head on thestorage source remains above the value Hc. As has been describedhereinabove the turbine. 3 isde-V signed and operative to drive thegenerator l at normal .operating speed under an averageiavai.-

able head between the values Trib and Hs, to theref by produce power atmaximum efficiency. It is presumed the value. Hc is predeterminedjatsuch a value as will produce reasonably Veiiicient operation of theturbine 3. When .the available head drops below such aV lower 'limitingvalue, the

sure disconnection of the generator iro'rnthelive circuit.

It will be apparent that ras the available head on the storage sourceagain-rises through yeral values Hc, Hb and Hs reverse operations occur,

as will be apparent :irornthe description lhereinabove, inap. orderwhich lirst renders the tilrbine 3 operative to drive generator l, .thenrenders the turbine 2 operative to. assist the turbine .3 as the headreaches the value Ht, and, `as .the head reaches the value lja, causestheturbine .3 to be rendered inactive, the turbine 2 alone continuing tofurnish the power requiredior the operation of the generator l. k

With the above described arrangement yofl the hydraulic and yelectricalfeatures of the installation whichpermits transferring the'load or powerrequiredfor operating the generator from one to .the other. of. theturbines' which are of such individualdesign and capacity as toefficiently supply iherequired power throughout the total variation inhead, the amountoij water used perv horsepower ldeveloped is reduced,vand` the. available water is economically and eiiiciently used; and thecapital investment vinvolved in the, installation is made to pay anVincreased return. Y l f .While the hydro-.electric unit described aboveiindsgreat utility when connected with a distribution systemwhoseirequency is definitely establishediby means .other thanthisparticular unit, nevertheless, it finds considerable utility when itis the only power unit connected to or establ-ish- Y efficient operationunder different heads, a power translating unit operatively connectibleturbines to be driven thereby, regulating means operatively associatedwith saidI turbines for causing either one alone or both oi'y saidturbines'to effectively drive said power translatingunit, land meansautomatically'. responsive vto the energy available at theturbineinlet-"for controlling said regulating means. n

2.*In combination, a power unit comprising a plural-ity oi iiuid drivenprime movers subject to operation under widelyv varying' fluid heads, apower translating device arranged tof be driven by either of ysaid primemovers,V and` governing means'including instrumentalities responsive toAthe available'luid head on saidl prime inoversior insuring operation ofsaid translating device by one or lthe-other of said primeinovers. 5

3. vIn a power system, a plurality of hydraulic turbines, a machinearranged to be driven thereby, means :for regulating the admission ofwater to saidI turbines, speed Vresponsive governinghmeansiorcontrolling the speed of said turbines to insure operation'thereof'at one predetermined speed under normal running conditions,` and`ineansresponsive to the effective head on said turbines. foradjusting,saidgoverning means to'V cause thev latter toin'surecontrolled operation of said driven machine by one ortheother of saidturbines alone depending upon the value or" lsaid effective head.

4. In a poweri system, aplurality of hydraulic turbines; apowertranslating unitl arranged to be ldriventhereby, means for regulatingthe yadmission of water .to said turbines, speedresponsive governingmeans iorcontrolling the `speed or' said turbines toiinsure operationthereof at apredetermined speed'under normal'running conditions, andmeans'responsive to the eiective head on said'turbines for adjustingsaidL governing means-to cause the latter-to :insure'controlledoperation of rsaid power translating unit byone or the --other ofsaidturbines alone or both of said turbines. i vi .Y

5. A hydraulic Vpower installa-tion;comprising a plurality of hydraulicturbines'designed for most eicient operation under different heads andsubjectv to a variable available supply of Water, a

vas

power translating unit arranged to be driven by either one of saidturbines, controlling means for said turbines operative to maintain apredetermined characteristic of the power output of said translatingunit under conditions of variable load thereon, and means automaticallyresponsive to a characteristic of the available head on said turbinesfor providing for eifective operation of said translating unit by eitherone of said turbines alone.

6. A power installation comprising a plurality of hydraulic turbinesdesigned for most efiicient operation under Widely different heads andsubject to a variable available supply of water, a power translatingunit arranged to be driven by either or both of said turbines, and meansresponsive to a characteristic of the available supply of water fordetermining which of said turbines is in effective power supplyingrelation to said translating device, whereby the eniciency of operationof said installation is sustained to an increased degree in spite ofoperation of said turbines under variable heads.

7. In combination, a power unit comprising a plurality of hydraulicturbines subject to operation from a storage source of widely varyinghead, a power translating device arranged to be driven by said turbines,and governing means ly varying head, a powertranslating unit arrangedrto be driven by said turbines, means for regulating the admission ofwater to said turbines speed responsive governing means for controllingthe speed of said turbines to insure operation there-- of at apredetermined speed under variable load conditions, and means responsiveto the effective head on said turbines for adjusting said governingmeans to cause the latter to insure the effective operation of saidpower translating unit by one or the other of lsaid turbines alone orboth'turbines together determined by the available head of saidV storagesource.

9. A power installation, comprising a plurality of hydraulic turbinessubject to operation under a widely varying range of head thereon, a malchine arranged to be driven by one or the other Y head to which saidturbines are subjected.

10. Apower installation for operation under conditions of widely varyinghead, comprising a plurality of hydraulic machines each designed formost efficient operation under a head different from that' for which theother is designed.A a power translating unit arranged to be driven byeither of said hydraulic machines, a power system connected to saidpower translating unit a characteristic of whose operation isestablished by means other than said power translating unit, andinstrumentalities automatically controlled in response to the availablehead to which said hydraulic machines are subjected for insuring undercertain conditions the transfer of energy between said power system andsaid power translating unit with only that one of said hydraulicmachines in effective operation which operates with the greaterefficiency under the head available at the time.

11. The method of operating a power installation comprising a pluralityof prime movers operable from a source of fluid energy of variableavailable energy supply and each designed for most efficient operationunder different conditions from the other as to available energy supplyat said source and arranged to drive a common load, which comprisesutilizing as the effective source of power for said load that one ofsaid prime movers which is designed for more efficient operation underthe condition of available energy supply existing at the particulartime, and changing from one to another of said prime movers for theeffective source of power for said load as the said condition ofavailable energy supply varies.

12. Method of operating a hydraulic power installation comprising aplurality of hydraulic turbines operable from a fluid supply undervariable head and each turbine designed for most efficient operationunder a head value different from the other turbine and said turbinesbeing arranged to supply energy` to a common load,

which comprises utilizing as the effective source Y of energy for saidload that one of said turbines whose most efficient operating head moreclosely approximates the head available for the turbines, and changingfrom one to another of said turbines as the effective source of energyfor said coinmon load as the head on said iiuid supply approaches themost efficient operating heads of the several turbines.

13. In a hydraulic power installation, the combination of a plurality ofhydraulic turbines subject to operation under varying values ofavailable head, means for converting the energy of said turbines andsupplying said energy to a common load, and controlling means forsaidturbines responsive to the available head thereon for insuring that theturbine capable of operation with greater efficiency at a particularvalue of availr able head supplies under such value of head a greaterproportion of its full load than the other turbine.

14. In a power installation, the combination of a plurality ofiiuid-operated prime movers subject to operationunder varying values ofinlet pressure, means for transmitting the energy of both of said primemovers to a common load, and controlling means for said prime moversresponsive to the available supply of energy for said prime movers forinsuring operation of one or the otherV or both of said prime moversdepending upon the value of said inlet pressure.

15. In a power installation, the combination of a plurality offluid-operated prime movers each designed for most efficient operationunder a different degree of inlet pressure from the other and subject tooperation from a source of fluid energy of variable available pressure,and controlling means for said prime movers lincluding means responsiveto the available-pressure of said energy source and operative undercertain pressure y ARNOLD PFAU' CERTFICATE 0F CORRECTION.

Parent No. 1,922,323. August i5, 1933.

ARNOLD PFAU.

it is hereby ertified that errm ppears in ille printed specification ofthe @have numbered pateri requiring orrerzticm as follows: Page 4, line1121, claim 2, aier "movers" insert "aione"; page 5, ine 37, claim 8,aiter "urbins" inser a crm-rma; and that rire said Leiers Parent shouldbe read with these correciins iaereiii rmr the same may conform to therecrd of the case in the Patent ffice.

Signed and saaled this 26th day of Sepember, A. 1 1933.

M. Hopkins (Seal) Acting Commissioner oi Patents.

CERTlFlCATE 0F CORRECTION.

Parent No. 1,922,323. August 15, 1933.

ARNOLD PFAU.

lt is hereby certified that error appears in the printed specificationoi the above numbered paten requiring correction as follows: Page 4,line 21, claim 2, after "movers" insert "alone"; page 5, line 37, claim8, after "turbines" insert a comme.; and that me said Leters Parentshould be read with these correcions merrain filmt the same may oonormto the record of the case in the Patent Office.

Signed aard sealed this 26th day of September, A. D. 19.33.

. M. Hopkins (Seal) Acting Commissioner of .Pertanto

